1. Field of Invention
The present invention relates to composite sampling systems and sampling valves therefor.
2. Description of Prior Art
Composite sampling systems, such as in U.S. Pat. No. 3,798,972 of Applicant, have been used to extract samples of fluid from conduit systems.
Rotatable or rotary valves are also known, as evidenced by U.S. Pat. Nos. 31,530; 2,314,031; 2,413,293; 3,195,776; 3,251,511; 3,403,827; and 3,506,237. However, certain of these valves were for insertion of solids into conduits, rather than sample removal. Others of these valves were for handling of solid matter and were specifically designed to prevent damage to the solid matter during valve operation.
However, in obtaining composite samples of effluent materials, two further considerations existed. First, an accurate sample of a fixed, predetermined volume must be repeatedly taken at particular intervals over a sampling operation period. Second, suspended matter or debris in the conduit system must not interfere with operation of the sampling system or vary the sample volume.